Method for determining characteristics of substrate employing fluid geometries

Abstract

The present invention provides a technique for determining characteristics of substrates, such as the presence of contaminants, shape, as well as the spatial relationships between spaced-apart substrates. The spatial relationships include distance and angular orientation, between first and second spaced apart substrates. The technique includes forming a volume of fluid on the second substrate, with the volume of fluid having an area associated therewith. The volume of fluid is compressed between the first and second substrates to effectuate a change in properties of the area, defining changed properties. The changed properties are sensed, and the characteristics of the first and second substrates are determined as a function of the changed properties.

1. A method for determining characteristics of first and second substrates, said method comprising:
 forming a volume of fluid on said second substrate said volume of fluid having an area associated therewith;  
 compressing said volume of fluid between said first and second substrates to effectuate a change in properties of said area, defining changed properties;  
 sensing said changed properties; and  
 determining characteristics of said first and second substrates as a function of said changed properties, defining measured characteristics.  
 
     
     
       2. The method as recited in  claim 1  wherein said changed properties are geometries selected from a set of geometries including size, shape and symmetry. 
     
     
       3. The method as recited in  claim 1  wherein said changed properties includes an expansion of said fluid to a predetermined position on said second substrate. 
     
     
       4. The method as recited in  claim 1  wherein forming said volume of fluid further includes depositing first and second spaced-apart drops of said fluid on said second substrate and compressing said volume further includes compressing said first and second drops to effectuate a change in a geometry of one of said first and second drops. 
     
     
       5. The method as recited in  claim 1  wherein forming said volume of fluid further includes depositing first and second spaced-apart drops of said fluid on said second substrate, with said first drop having a first geometry associated therewith and said second drop having a second geometry associated therewith, with forming said volume of fluid further including depositing said first and second spaced-apart drops of said fluid on said second substrate and compressing said volume further includes compressing said first and second drops to effectuate a change in said first geometry, defining a changed geometry, and further including comparing said changed geometry with said second geometry to determine differences therebetween, defining a variance, with determining said characteristics further including determining said characteristics as a function of said variance. 
     
     
       6. The method as recited in  claim 1  wherein determining said characteristics further includes determining a distance between said first and second substrates. 
     
     
       7. The method as recited in  claim 1  wherein determining said characteristics further includes determining whether said first and second substrates extend parallel to one another. 
     
     
       8. The method as recited in  claim 1  wherein said first substrate lies in a first plane and said second substrate lies in a second plane forming an angle with said first plane, with determining said characteristics further including determining said angle. 
     
     
       9. The method as recited in  claim 1  wherein sensing said changed properties further includes acquiring a first image of a region of said second substrate in which said volume is located before compressing said volume of fluid and acquiring a second image of said region after compressing said volume of fluid and comparing information in said first and second images associated with said volume of fluid. 
     
     
       10. The method as recited in  claim 1  wherein said characteristics are selected from a set of characteristics consisting of a presence of contamination, a spatial relationship, and shape. 
     
     
       11. The method as recited in  claim 10  further including adjusting said spatial relationship between said first and second substrates in response to said measured spatial relationship to obtain a desired spatial relationship. 
     
     
       12. A method for determining spatial relationships between a first substrate, lying in a first plane, and a second substrate, lying in a second plane, said method comprising:
 forming a volume of fluid on said second substrate, said volume of fluid having an area associated therewith;  
 compressing said volume of fluid between said first and second substrates to effectuate a change in properties of said area, defining changed properties, with said changed properties being selected from a set of properties including size, shape and symmetry;  
 sensing said changed properties; and  
 determining a spatial relationship between said first and second substrates as a function of said changed properties, defining a measured spatial relationship, with said spatial relationship selected from a set of relationships including distance between said first and second planes, and an angle formed between said first and second planes.  
 
     
     
       13. The method as recited in  claim 12  wherein forming said volume of fluid further includes depositing first and second spaced-apart drops of said fluid on said second substrate and compressing said volume further includes compressing said first and second drops to effectuate a change in the area of said first drop, defining a changed first area, and further including comparing the area of said changed first area with the area of said second drop to determine differences therebetween, defining a variance, with determining said spatial relationship further including determining said spatial relationship between said first and second substrates as a function of said variance. 
     
     
       14. The method as recited in  claim 12  wherein sensing said changed area further includes acquiring a first image of a region of said second substrate in which said volume of fluid is located before compressing said volume of fluid and acquiring a second image of said region after compressing said volume of fluid and comparing information in said first and second images associated with said volume of fluid. 
     
     
       15. The method as recited in  claim 13  adjusting said spatial relationship between said first and second substrates in response to said measured spatial relationship to obtain a desired spatial relationship. 
     
     
       16. A method for determining characteristics of first and second substrates, said method comprising:
 forming a volume of fluid on said second substrate, said volume of fluid having an area associated therewith;  
 moving fluid associated with said volume over said second substrate to effectuate a change in properties of said area, defining changed properties;  
 sensing said changed properties; and  
 determining characteristics of one of said first and second substrates as a function of said changed properties, defining measured characteristics.  
 
     
     
       17. The method as recited in  claim 16  wherein said changed properties are geometries selected from a set of geometries including size, shape and symmetry. 
     
     
       18. The method as recited in  claim 16  wherein said changed properties includes an expansion of said fluid to a predetermined position on said second substrate. 
     
     
       19. The method as recited in  claim 16  wherein forming said volume of fluid further includes depositing first and second spaced-apart drops of said fluid on said second substrate and moving further includes compressing said first and second drops to effectuate a change in a geometry of one of said first and second drops. 
     
     
       20. The method as recited in  claim 16  wherein forming said volume of fluid further includes depositing first and second spaced-apart drops of said fluid on said second substrate, with said first drop having a first geometry associated therewith and said second drop having a second geometry associated therewith, with forming said volume of fluid further including depositing said first and second spaced-apart drops of said fluid on said second substrate and compressing said volume further includes compressing said first and second drops to effectuate a change in said first geometry, defining a changed geometry, and further including comparing said changed geometry with said second geometry to determine differences therebetween, defining a variance, with determining said characteristics further including determining said characteristics as a function of said variance. 
     
     
       21. The method as recited in  claim 16  wherein determining said characteristics further includes determining a distance between said first and second substrates. 
     
     
       22. The method as recited in  claim 16  wherein determining said characteristics further includes determining whether said first and second substrates extend parallel to one another. 
     
     
       23. The method as recited in  claim 16  wherein said first substrate lies in a first plane and said second substrate lies in a second plane forming an angle with said first plane, with determining said characteristics further including determining said angle. 
     
     
       24. The method as recited in  claim 16  wherein sensing said changed properties further includes acquiring a first image of a region of said second substrate in which said volume is located before compressing said volume of fluid and acquiring a second image of said region after compressing said volume of fluid and comparing information in said first and second images associated with said volume of fluid.